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Changing the Dietary Guidelines

If you have been following any of the Dietary Guidelines Advisory Committee’s meetings (who does that anyway? I mean, unless you are a total geek like I am), then you might have noticed that the next Guidelines seem very likely to continue to promote the same nutritional advice that has proven largely ineffective for more than 35 years.

In my other, not-quite-so-snarky, life, I am not Wonder Woman (but oh, what I wouldn’t give for a pair of bracelets of submission). However, I am director of the Healthy Nation Coalition, a loose affiliation of healthcare and public health professionals, scientists, and concerned citizens who think it is time we did nutrition a little differently. Right now, we are creating a coalition of supporters to speak out against the direction the current 2015 Dietary Guidelines are taking and to offer an alternative approach.

This letter will be delivered to the Secretaries of the U.S. Departments of Agriculture and Health and Human Services, selected policymakers, and interested media outlets. We hope to add to the momentum that has been building in the national media calling for a change in our national dietary guidance (see Nina Teicholz’ book, Big Fat Surprise, and her recent op-ed in the Wall Street Journal).

The letter is copied below (or you can use this link to the pdf–the pdf is where all the citations are, because I know how you love citations).

In a nutshell, we are asking for Dietary Guidelines that are geared toward the general public and focused on adequate essential nutrition.

This is not a call for low-carb, high-fat dietary recommendations, or paleo ones, and it takes no stance on the whole “calories in, calories out” versus hormonal regulation etc. etc. issue. So if you want to criticize this approach, don’t start bitching about low-carb diets or CICO, or I’ll know that you haven’t bothered to actually read this and I won’t feel guilty about deleting your comments. Beyond that, if you have genuine objections to this approach, suggest a better one–or go away. What we are doing now isn’t working. What we need is productive conversation about what to do differently.

At the conclusion of the sixth meeting of the 2015 Dietary Guidelines Advisory Committee (DGAC), we write to express concern about the state of federal nutrition policy and its long history of failure in preventing the increase of chronic disease in America. The tone, tenor, and content of the DGAC’s public meetings to date suggest that the 2015 Dietary Guidelines for Americans (DGA) will perpetuate the same ineffective federal nutrition guidance that has persisted for nearly four decades but has not achieved positive health outcomes for the American public.

We urge you to adhere to the initial Congressional mandate that the DGA act as “nutritional and dietary information and guidelines for the general public” and are “based on the preponderance of the scientific and medical knowledge which is current at the time the report is prepared.”

Below we lay out specific objections to the DGA:
· they have contributed to the increase of chronic diseases;
· they have not provided guidance compatible with adequate essential nutrition;
· they represent a narrow approach to food and nutrition inconsistent with the nation’s diverse cultures, ethnicities, and socioeconomic classes;
· they are based on weak and inconclusive scientific data;
· and they have expanded their purpose to issues outside their original mandate.

As you prepare to consider the 2015 DGAC’s recommendations next year, we urge you to fulfill your duty to create the dietary foundation for good health for all Americans by focusing on adequate essential nutrition from whole, nourishing foods, rather than replicating guidance that is clearly failing.

The DGA have contributed to the rapid rise of chronic disease in America.

In 1977, dietary recommendations (called Dietary Goals) created by George McGovern’s Senate Select Committee advised that, in order to reduce risk of chronic disease, Americans should decrease their intake of saturated fat and cholesterol from animal products and increase their consumption of grains, cereal products, and vegetable oils. These Goals were institutionalized as the DGA in 1980, and all DGA since then have asserted this same guidance. During this time period, the prevalence of heart failure and stroke has increased dramatically. Rates of new cases of all cancers have risen. Most notably, rates of diabetes have tripled. In addition, although body weight is not itself a measure of health, rates of overweight and obesity have increased dramatically. In all cases, the health divide between black and white Americans has persisted or worsened.

While some argue that Americans have not followed the DGA, all available data show Americans have shifted their diets in the direction of the recommendations: consuming more grains, cereals, and vegetable oils, while consuming less saturated fat and cholesterol from whole foods such as meat, butter, eggs, and full-fat milk. Whether or not the public has followed all aspects of DGA guidance does not absolve the U.S. Departments of Agriculture (USDA) and Health and Human Services (DHHS) from ensuring that the dietary guidance provided to Americans first and foremost does no harm.

The 1977 Dietary Goals marked a radical shift in federal dietary guidance. Before then, federal dietary recommendations focused on foods Americans were encouraged to eat in order to acquire adequate nutrition; the DGA focus on specific food components to limit or avoid in order to prevent chronic disease. The DGA have not only failed to prevent chronic disease, in some cases, they have failed to provide basic guidance consistent with nutritionally adequate diets.
· Maillot, Monsivais, and Drewnowski (2013) showed that the 2010 DGA for sodium were incompatible with potassium guidelines and with nutritionally adequate diets in general.
· Choline was recognized as an essential nutrient in 1998, after the DGA were first created. It is crucial for healthy prenatal brain development. Current choline intakes are far below adequate levels, and choline deficiency is thought to contribute to liver disease, atherosclerosis and neurological disorders. Eggs and meat, two foods restricted by current DGA recommendations, are important sources of choline. Guidance that limits their consumption thus restricts intake of adequate choline.
· In young children, the reduced fat diet recommend by the DGA has also been linked to lower intakes of a number of important essential nutrients, including calcium, zinc, and iron.

Following USDA and DHHS guidance should not put the most vulnerable members of the population at risk for nutritional inadequacy. DGA recommendations should be emphasizing whole foods that provide essential nutrition, rather than employing a reductionist approach based on single food components to exclude these foods from the diet.

The DGA’s narrow approach to food and health is inappropriate for a diverse population.

McGovern’s 1977 recommendations were based on research and food patterns from middle class Caucasian American populations. Since then, diversity in America has increased, while the DGA have remained unchanged. DGA recommendations based on majority-white, high socioeconomic status datasets have been especially inappropriate for minority and low-income populations. When following DGA recommendations, African American adults gain more weight than their Caucasian counterparts, and low-income individuals have increased rates of diabetes, hypertension, and high cholesterol. Long-standing differences in environmental, genetic and metabolic characteristics may mean recommendations that are merely ineffective in preventing chronic disease in white, middle class Americans are downright detrimental to the long-term health of black and low-income Americans.

The DGA plant-based diet not only ignores human biological diversity, it ignores the diversity of American foodways. DGA guidance rejects foods that are part of the cultural heritage of many Americans and indicates that traditional foods long considered to be important to a nourishing diet should be modified, restricted, or eliminated altogether: ghee (clarified butter) for Indian Americans; chorizo and eggs for Latino Americans; greens with fatback for Southern and African Americans; liver pâtés for Jewish and Eastern European Americans.

Furthermore, recommendations to prevent chronic disease that focus solely on plant-based diets is a blatant misuse of public health authority that has stymied efforts of researchers, academics, healthcare professionals, and insurance companies to pursue other dietary approaches adapted to specific individuals and diverse populations, specifically, the treatment of diabetes with reduced-carbohydrate diets that do not restrict saturated fat. In contradiction of federal law, the DGA have had the effect of limiting the scope of medical nutrition research sponsored by the federal government to protocols in line with DGA guidance.

The DGA are not based on the preponderance of current scientific and medical knowledge.

The science behind the current DGA recommendations is untested and inconsistent. Scientific disagreements over the weakness of the evidence used to create the 1977 Dietary Goals have never been settled. Recent published accounts have raised questions about whether the scientific process has been undermined by politics, bias, institutional inertia, and the influence of interested industries.

Significant scientific controversy continues to surround specific recommendations that:
1. Dietary saturated fat increases the risk of heart disease: Two recent meta-analyses concluded there is no strong scientific support for dietary recommendations that restrict saturated fat. Studies cited by the 2010 DGAC Report demonstrate that in some populations, lowering dietary saturated fat actually worsens some biomarkers related to heart disease.
2. Dietary cholesterol increases the risk of heart disease: Due to a lack of evidence, nearly all other Western nations have dropped their limits on dietary cholesterol. In 2013, a joint panel of the American Heart Association and the American College of Cardiology did the same.
3. Polyunsaturated vegetable oils reduce the risk of heart disease and should be consumed as the primary source of dietary fat: Recent research renews concerns raised in response to the 1977 Dietary Goals that diets high in the omega-6 fatty acids present in vegetable oils may actually increase risk of chronic disease or death.
4. A diet high in carbohydrate, including whole grains, reduces risk of chronic disease: Clinical trials have demonstrated that diets with lower carbohydrate content improve risk factors related to heart disease and diabetes. Janet King, Chair of the 2005 DGAC, has stated that “evidence has begun to accumulate suggesting that a lower intake of carbohydrate may be better for cardiovascular health.”
5. A low-sodium diet reduces risk of chronic disease: A 2013 Institute of Medicine report concludes there is insufficient evidence to recommend reducing sodium intake to the very low levels set by the DGA for African-Americans of any age and adults over 50.

In all of these cases, contradictory evidence has been ignored in favor of maintaining outdated recommendations that have failed to prevent chronic disease.

More generally, “intervention studies, where diets following the Dietary Guidelines are fed long-term to human volunteers, do not exist,” and food patterns recommended by the DGA “have not been specifically tested for health benefits.” The observational research being used for much of the current DGAC activities may suggest possible associations between diet and disease, but such hypotheses must then be evaluated through rigorous testing. Applying premature findings to public health policy without adequate testing may have resulted in unintended negative health consequences for many Americans.

The DGA have overstepped their original purpose.

The DGA were created to provide nutrition information to all Americans. However, the current 112-page DGA, with 29 recommendations, are considered too complex for the general public and are directed instead at policymakers and healthcare professionals, contradicting their Congressional mandate.

Federal dietary guidance now goes far beyond nutrition information. It tells Americans how much they should weigh and how to lose weight, even recommending that each American write down everything that is eaten on a daily basis. This focus on obesity and weight loss has contributed to extensive and unrecognized “collateral damage”: fat-shaming, eating disorders, discrimination, and poor health from restrictive food habits. At the same time, researchers at the Centers for Disease Control have shown that overweight and obese people are often as healthy as their “normal” weight counterparts. Guidance related to body weight should meet individual health requirements and be given by a trained healthcare practitioner, not be dictated by federal policy.

The DGA began as an unmandated consumer information booklet. They are now a powerful political document that regulates a vast array of federal programs and services, dictates nationwide nutrition standards, influences agricultural policies and health-related research, and directs how food manufacturers target consumer demand. Despite their broad scope, the DGA are subject to no evaluation or accountability process based on health outcomes. Such an evaluation would demonstrate that they have failed to fulfill their original goal: to decrease rates of chronic disease in America.

Despite this failure, current DGAC proceedings point to an expansion of their mission into sustainable agriculture and environmental concerns. While these are important issues, they demonstrate continued “mission creep” of the DGA. The current narrow DGA focus on plant-based nutrition suggests a similarly biased approach will be taken to environmental issues, disregarding centuries of traditional farming practices in which livestock play a central role in maintaining soil quality and ecological balance. Instead of warning Americans not to eat eggs and meat due to concerns about saturated fat, cholesterol, and obesity, it is foreseeable that similar warnings will be given, but for “environmental” reasons. This calls for an immediate refocusing of the purpose of the DGA and a return to nutritional basics.

Solution: A return to essential nutrition guidance

As our nation confronts soaring medical costs and declining health, we can no longer afford to perpetuate guidelines that have failed to fulfill their purpose. Until and unless better scientific support is secured for recommendations regarding the prevention of chronic disease, the DGA should focus on food-based guidance that assists Americans in acquiring adequate essential nutrition.

Shifting the focus to food-based guidance for adequate essential nutrition will create DGA that:
· are based on universally accepted and scientifically sound nutritional principles: Although more knowledge is needed, the science of essential nutrient requirements is firmly grounded in clinical trials and healthcare practice, as well as observational studies.
· apply to all Americans: Essential nutrition requirements are appropriate for everyone. Lack of essential nutrients will lead without exception to diseases of deficiency.
· include traditionally nourishing foods: A wide variety of eating patterns can provide adequate essential nutrition; no nourishing dietary approaches or cultural food traditions would be excluded or discouraged.
· expand opportunities for research: With dietary guidance focused on adequate essential nutrition, researchers, healthcare providers, and insurance companies may pursue dietary programs and practices tailored to individual risk factors and diverse communities without running afoul of the DGA and while ensuring that basic nutrition needs are always met.
· direct attention towards health and well-being: Focus will be directed away from intermediate markers, such as weight, which may be beyond individual control, do not consistently predict health outcomes, and are best dealt with in a healthcare setting.
· are clear, concise, and useful to the public: Americans will be able to understand and apply such guidance to their own dietary patterns, minimizing the current widespread confusion and resentment resulting from federal dietary guidance that is poorly grounded in science.

It is the duty of USDA and DHHS leadership to end the use of controversial, unsuccessful and discriminatory dietary recommendations. USDA and DHHS leadership must refuse to accept any DGA that fail to establish federal nutrition policy based on the foundation of good health: adequate essential nutrition from wholesome, nourishing foods. It is time to create DGA that work for all Americans.

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28 thoughts on “Changing the Dietary Guidelines”

You write:
“The current narrow DGA focus on plant-based nutrition suggests a similarly biased approach will be taken to environmental issues, disregarding centuries of traditional farming practices in which livestock play a central role in maintaining soil quality and ecological balance.”

In what way do DGs slightly emphasizing plant-based nutrition suggest the “disregarding of centuries…” etc.? If I eat somewhat more vegetables than I am accustomed to, am I thereby “disregarding centuries…” etc.?

You write:
“Instead of warning Americans not to eat eggs and meat due to concerns about saturated fat, cholesterol, and obesity, it is foreseeable that similar warnings will be given, but for “environmental” reasons.”

Why is the word “environmental” in the above sentence surrounded by quotation marks? Quote marks generally mean that the thing being quoted is a misnomer, or does not really exist. Is that your intention? Also: do you think the government ought not give advice or guidance based on environmental concerns (assuming that you believe that there exist environmental concerns)?

We may have a fundamental disagreement about the nature of the emphasis of plant-based foods in the 2015 DGAC report. I am suggesting that since meat and poultry were both left off of the “healthy dietary pattern” identified by the DGAC that this is a more than “slight” emphasis on plant-based nutrition. Rather, the emphasis is on decreasing foods from animals and increasing “plant-based foods” (notice that this is not the same thing as vegetables, which are actual plants, not “plant-based foods,” although I supposed vegetables may be a subset of “plant-based foods,” especially if you grind them up with some corn and soy and turn them into a “plant-based product”).

Scare quotes can be used for many reasons, and my reasons for using them here are that the DGAC’s “environmental” concerns are constructed within a context where there are already a number of value-laden assumptions regarding what diet is “best.” Thus I find it impossible to extract what might actually be an environmental impact from the larger value-laden context in which initial assumptions about what we should and should not be eating are unlikely to be contradicted.

Here’s a thought experiment: Let’s pretend for a moment that 35 years of nutrition science and dietary guidance had firmly established that a diet that greatly reduces or eliminates animal products was detrimental to the health of Americans. When the models for evaluating the environmental impact of diets are set up, what are the chances of the model demonstrating that the extremely healthful (as determined by scientific consensus) diet–the one that contains animal products–is also one that is bad for the environment?

You might argue that the models would have to show that this diet is bad for the environment because that is WHAT IS, but these models are not material reality, only a representation of it. All of the knowledge claims about the environmental impact of particular dietary patterns are based on models that carry forward certain assumptions. Estimations are presupposed; values are assigned. Decisions are made about what factors go into a model and how they are used, and what factors are left out. In the best possible world, stakeholders would all agree on the assumptions that go into the models, including health impact of diet (which in turn has its own impact on the environment), but that has not been the case regarding public health nutrition guidance for nearly 40 years now.

Do you suppose that the models used by the DGAC include the medical waste from dialysis machines and wound clinics for people with amputations related to diabetes, a chronic disease whose incidence has increased dramatically since we started telling people what to eat to prevent chronic disease?

Environmental concerns should be the focus of experts who have knowledge and experience in the complex features of and interactions within our agricultural system. The DGAC are not those folks. And as I’ve said before, if the Dietary Guidelines prevent negative environmental outcomes the same way they prevented obesity and chronic disease, then we are all in big trouble.

“The dietary pattern characteristics being recommended by the 2015 DGAC reaffirm the dietary pattern characteristics recommended by the 2010 DGAC.” [which included recommendations to use flesh foods and other animal products in moderation]

and:

“The overall body of evidence examined by the 2015 DGAC identifies that a healthy dietary pattern is higher in vegetables, fruits, whole grains, low- or non-fat dairy, seafood, legumes, and nuts; moderate in alcohol (among adults); lower in red and processed meat;1 and low in sugar-sweetened foods and drinks and refined grains.”

Right. Eminently sensible advice, and I would think non-controversial. Who could possibly disagree with at least 90% of that? Lower sugar, moderate alcohol, more veggies, and so on. I mean, maybe one could natter about some detail; say, non-approval of grains, and preference for starchless or root veggies. But come on! By and large this is a non-controversial statement. No reasonable, nutrition-literate person could have any major objection.

Note the words: “lowER in red meat”, not FREE FROM red and processed meat. Also, elsewhere they specifically mention the health value of fish. I cannot find any statements suggesting an extreme vegetarian or vegan bias, or any such bias at all save for a luke-warm, modest suggestion to emphasize more plant foods and less animal foods.

Am I missing something? Perhaps you can provide a specific quote.

You write:
“Rather, the emphasis is on decreasing foods from animals and increasing “plant-based foods” (notice that this is not the same thing as vegetables…”

They specifically state that “plant-based foods” means “vegetables, fruits, whole grains, legumes, nuts, and seeds”. That’s a verbatim quote. That is a sensible definition, I think.

You are correct that the emphasis is on decreasing animal foods and increasing plant foods. Is that wrong? Americans eat vast quantities of meat and other animal foods, as you well know. Do you think they should eat more? And less vegetation? Seriously?

Regarding the environmental issue, I am finding comments like these (again from the exec summary linked above):

“The major findings regarding sustainable diets were that a diet higher in plant-based foods, such as vegetables, fruits, whole grains, legumes, nuts, and seeds, and lower in calories and animal-based foods is more health promoting and is associated with less environmental impact than is the current U.S. diet. This pattern of eating can be achieved through a variety of dietary patterns, including the Healthy U.S.-style Pattern, the Healthy Mediterranean-style Pattern, and the Healthy Vegetarian Pattern. All of these dietary patterns are aligned with lower environmental impacts and provide options that can be adopted by the U.S. population.”

Again, I find this to be eminently sensible and, I would hope, non-controversial. I am a natural skeptic and contrarian; I like to argue; I would have no trouble condemning the report writers — no matter how “high-level” and official — if they had written an ideological tract. But that is not what I found when I read their actual words. Rather, I find it hard to believe that anyone would seriously disagree with, e.g., the sentences immediately above. Note that, once again, a radical vegan or vegetarian agenda is NOT being pushed; they specifically mention a “Healthy U.S.-style Pattern” which includes animal foods in moderate amounts.

You wrote:
“chronic disease…incidence has increased dramatically since we started telling people what to eat to prevent chronic disease”

Do you think that this has anything to do with official dietary recommendations? I don’t. Americans eat a TERRIBLE diet: tons of sugar, zillions of empty calories in the form of fats and refined carbs, almost no vegetables, low fiber, low micronutrients, and on and on. It is a disaster. And as a result, chronic disease is on the rise.

It is true that Americans eat SLIGHTLY less fat and more carbs than they did years ago, but the difference is so small that it could not possibly account for anything. According to analyses of NHANES, fat went from 36.6 to 33.7% of total energy intake. That’s tiny. Adjusting the fat:carb ratio has beneficial effects sometimes, but only at the extremes; i.e. when you cut carbs to near-nothing, or when you cut fats to under 10-15%. Otherwise there’s no effect.

The rise of chronic disease very likely had nothing at all to do with fat:carb ratio in the diet, and everything to do with excess calories overall, excess refined foods (extrinsic fats and sugars), low fiber, low micronutrients, too high of a glycemic load, and so on. And, also, other obesogenic and pathogenic influences (TV and internet, sleep deficit, light pollution, and other stuff).

The official dietary recommendations, years ago, were correct enough; they just got co-opted and perverted by the corporate complex.

vis: David Katz:http://www.huffingtonpost.com/david-katz-md/diet-and-nutrition_b_4755777.html
“consider that the advice we got decades ago to cut dietary fat was never intended as advice to eat low-fat, high-starch, high-sugar cookies. When the advice to cut fat was first provided, there was no such thing as highly-processed, low-fat junk food. The food industry exploited the advice and invented low-fat junk food to take advantage of it…. The advice to cut fat was intended to direct us to the naturally low-fat foods that existed at the time, namely vegetables, fruits, beans, lentils, whole grains, and lean meats. Does anyone doubt that if America ran mostly on such foods (rather than, as Madison Avenue seemingly now contends, donuts and coffee) our health would be much better? I do not.”

And neither do I. And neither does any other sensible, intelligent, nutritionally-literate person.

By the way, you seem to be anxious to defend traditional animal husbandry and associated animal foods production. That’s fine. I defend it, too. In fact, I am a big fan of INCREASING animal husbandry and animal food production and consumption in the less-developed world, where it is truly needed. Anyway, you need not defend, since no one is attacking — at least not that I know of. Certainly not the DGAC.

I haven’t said the DGAC promotes a “radical vegetarian or vegan agenda” (here or anywhere else that I know of). That’s what Alan said I said. But the implication is clear: Anyone who would consider this “eminently sensible” and “reasonable” document as “radical” or “extreme” must herself be an extremist and therefore pretty bogus.

Now, let’s see how many times Alan presents his own argument and that of the DGAC as “reasonable”:

eminently sensible
non-controversial
Who could possibly disagree
this is a non-controversial statement
No reasonable, nutrition-literate person could have any major objection.
modest suggestion
That is a sensible definition
eminently sensible [again]
non-controversial [again]
sensible, intelligent, nutritionally-literate

Whew. Has Alan has been reading too much David Katz? (Answer: He has.)

Lest I be accused of “tu quoque” and not actually addressing Alan’s arguments:

From the DGAC Report: “The overall body of evidence examined by the 2015 DGAC identifies that a healthy dietary pattern is higher in vegetables, fruits, whole grains, low- or non-fat dairy, seafood, legumes, and nuts; moderate in alcohol (among adults); lower in red and processed meat;1 and low in sugar-sweetened foods and drinks and refined grains.” Nowhere is “meat” mentioned except when qualified by “red” and “processed.” Poultry is not mentioned at all. What about, y’know, just plain ol’ meat? Where’s that?

From Alan: “Who could possibly disagree with at least 90% of that? Lower sugar, moderate alcohol, more veggies, and so on” [emphasis mine]. Well, me, I guess. Because …

Fruits are not veggies.
Whole grains are not veggies.
Low- and non-fat dairy are not veggies.
Seafood is not veggies.
Nuts are not veggies.
Legumes are only veggies sometimes.

So out of the 7 things they mention as what identifies a “healthy dietary pattern,” at most 1.5 of these are veggies. And yet Alan reads this as a recommendation for “more veggies.” We may be reading the same document, but we’re certainly not reading it the same way.

And just to point out, the way the list is written, the implication is alcohol is more closely identified with a “healthy dietary pattern” than “red or processed meat.” I suppose that as soon as my son turns 21, I should snatch that burger out of his hands and replace it with a beer, as part of a “healthy dietary pattern.” Yeah, no potential problems there.

Alan suggests the DGAC’s wording is but a “modest” suggestion to “emphasize more plant foods and less animal foods.”
–“modest” – A rhetorical move to indicate the inherent reasonableness of this notion. See above.
–“emphasize” – So they aren’t suggesting any changes in eating behavior, just changes in how we speak–more or less emphatically?–about these foods?
–“more plant foods” – Yup. Not veggies. But plant foods. See below.
–“less animal foods” – Um, “fewer” animal foods? It would be “less animal food” because food is a non-countable noun here, but “foods” are countable, thus “fewer.” Just sayin’.

[Me]: “Rather, the emphasis is on decreasing foods from animals and increasing “plant-based foods” (notice that this is not the same thing as vegetables…”

[Alan, in response to me, above]: They specifically state that “plant-based foods” means “vegetables, fruits, whole grains, legumes, nuts, and seeds”. That’s a verbatim quote. That is a sensible definition, I think.

Since 1970, the biggest increases in consumption have come from “plant foods” – vegetable oils and flour and cereal products (because when you get granular about the data around fats and oils, it’s really just all about oil). The only “animal foods” that we’ve increased our consumption of since 1970 are poultry and fish, and the increase calories contributed by these two categories of “animal foods” isn’t even half of the increase in number of calories contributed by flour and cereal products. Not looking too “vast” from this perspective.

Alan states that the “TERRIBLE” diet of Americans has nothing to do with official dietary recommendations. Well, that seems pretty unlikely seeing as the official dietary recommendations affect every aspect of our food environment, from food production and manufacturing to labeling to research to nutrition education to what shows up in your grocery stores and what you’re told by health care professionals. I mean, the fact that we have chicken wings as fast food to snack on is because the push to get Americans to consume lean poultry led to the appearance of skinless chicken breasts (leaner than dark meat), which then freed up a bunch of wings that could then be fried up & coated in butter and hot sauce. Before the DGA came along, the folks trying to get buffalo wings to catch on as a national sensation simply didn’t have enough wings to do it with because–back in the day–the wings came attached to the breasts, skin and all. So when national policy was created to tell people what to eat and what not to eat in order to prevent chronic disease, I can’t imagine how any sensible, intelligent, nutritionally-literate person would think that there could possibly be zero effect. And, in fact, Alan’s quote from David Katz seems to argue against this.

Read that quote again–slowly and carefully– and tell me where the problem is located. Okay, I’ll help you out:

From David Katz: “… the advice we got decades ago to cut dietary fat was never intended as advice to eat low-fat, high-starch, high-sugar cookies.” The advice might not have been intended to result in the consumption of Snackwells, but the implication is that it nevertheless had that effect. See? Effect.

So, then, where is the real origin of this problem? Shame on you, Evil Food Industry, for creating products that fit the dietary advice that was being given out? Shame on you, greedy lazy Americans, for not staying at home and making low-fat (replace the butter with applesauce!) wholegrain lentil and carob cookies? Maybe, just maybe, we should have left well enough alone and not have given out that (untested, unsubstantiated, controversial) advice in the first place.

Also David Katz: “The advice to cut fat was intended to direct us to the naturally low-fat foods that existed at the time, namely vegetables, fruits, beans, lentils, whole grains, and lean meats.” I get that this may have been the intention. But WHYYYYYY? We were neither fat nor sick at the time. Why the hell did we need to switch from eggs to (wholegrain) bagels? Give up our pork chops for (wholegrain) pasta? So the guidelines were well-intentioned. Fine. The science at the time was inconclusive and contradictory regarding a shift toward a more plant-based diet. At the time, these guidelines had not (and still have not) been tested for effectiveness. And, potential negative consequences were dismissed out of hand. The assumption was ONLY positive outcomes could possibly result from giving Americans advice to eat food that they didn’t currently eat–and hadn’t eaten much of before (except during times of deprivation or war)–in order to protect them from diseases they didn’t have. Yes, that’s “eminently sensible.”

On a more personal level, I am a person who got fat and sick eating a low-fat, vegetarian, home-cooked diet. I counted my calories. I exercised. It didn’t work & in fact, it made things worse. This is where Alan gets to tell me I was somehow deluding myself, cuz I love that part 🙂

I thought I was an anomaly until I met a few hundred people who struggled to be healthy while “eating right” and exercising. Yeah, I know, they were all deluding themselves too. But hey, know what happens when you tell people to cut back on whole grains and legumes and fruit? They don’t eat more meat or fat. They eat more veggies. Go figure.

Alan — once you locate and remove your gonads from the vicinity of your adam’s apple, you might want to reconsider having this kind of argument with someone who knows way more about nutrition than you do. And way more about the innards of the DGAC. And way more about the downstream effects of public policy decisions. And while we’re at it, obviously way, way, way more about rhetoric.

I mean, I found it quite entertaining and all, but in the uncomfortable way like watching one of those “fail” youtube videos where someone injures themselves trying to do something “badass.” Funny, but not very pretty.

Adele wrote:
“I haven’t said the DGAC promotes a “radical vegetarian or vegan agenda” (here or anywhere else that I know of). That’s what Alan said I said.”

No, I did not say that. I made ONE remark (amidst an approximately 1000-word post) about how the DGAC was not advancing a “radical veg/vegan agenda”. That is the truth. They are not.

Adele, you do not have to personalize everything. That comment was not directed at you specifically. I was writing a post that responded to you, but more important than that, I was looking at the DGAC, and noting what they were and were not saying. Copische?

Adele:
“But the implication is clear: Anyone who would consider this “eminently sensible” and “reasonable” document as “radical” or “extreme” must herself be an extremist and therefore pretty bogus.”

I don’t think you are an extremist. I don’t know where you got that idea. However, I think your interpretation and critique of the DGAC is mistaken.

Adele:
“Has Alan has been reading too much David Katz? (Answer: He has.)”

I don’t know what “too much” is. I’ve read about three articles authored by Katz. I enjoyed them. I found him to be intelligent, well-informed and persuasive. Am I supposed to apologize for this?

Adele:
“Nowhere is “meat” mentioned except when qualified by “red” and “processed.” Poultry is not mentioned at all.”

Adele, apparently you are not reading the same documents that I am. In the executive summary that I linked is this statement: “When reviewing the evidence, the Committee attempted to adhere to the language used by the study authors in describing food groupings. There was variability across the food groupings, and this was particularly apparent in the meat group. For example, “total meat” may have been defined as “meat, sausage, fish, and eggs,” “red meat, processed meat, and poultry,” or various other combinations of meat.”

See? Poultry is part of the meat group. Because it was not specified by name in each instance does not mean that they think it does not exist or ought not be eaten. They recommend less red and processed meat. They expect people to continue eating the “meat group”, which includes poultry and fish.

Adele:
““Vast” is a relative term that only makes sense when discussed in relation to some other measure(s).”

I’m sorry, Adele, but Americans do indeed consume vast amounts of meat by any measure, and more than ever over the last half-century. See here, and go to Table 2-1 on page 3:http://www.usda.gov/factbook/chapter2.pdf

You will note that total meat consumption has increased from 138 pounds per capita per year in the 1950s to 195 pounds in the 2000s. That’s an enormous increase. Egg consumption has gone down, but meat consumption is way up. Meat consumption in the U.S. is far in excess of that in the less-developed world. Nearly four pounds per week per capita, in the U.S.

Here’s a question: if we really require that much meat, then what of the several billion people who eat a small fraction of that much, or even none at all? Why are they now living instead of dead? That is, if such quantities of meat are truly a requirement.

Well, it should unnecessary to argue for the obvious reality: that much meat, or even nearly that much meat, is clearly NOT a requirement for life.

On the other hand, it is also true that a couple billion of the people I just mentioned ARE suffering from lack of nutrients found most abundantly, or even exclusively, in animal foods in general, and meat in particular. At least two billion people are deficient in iron, retinol and iodine — found in greatest amount, or even exclusively (retinol), or in the most-absorbable form (iron), in animal foods. That is not to mention a bevy of other compounds in animal foods, some of which are essential nutrients, other of which are conditionally essential, and still other of which are desirable and health-promoting, even if not essential at all.

This is the paradox that ideologue veg*n types, as well as anti-veg*n types, fail to understand. Animal foods are a real requirement for health (and also desirable, beyond bare requirement) for a great many people. But, at the same time, it is obvious that animal foods at the levels consumed by Americans are NOT a real requirement, and may (MAY) at such high levels even be pathogenic. It is funny to me that the anti-meat AND the pro-meat factions both fail to understand this, when it is quite obvious based on unarguable statistics as well as common-sense observations.

You see, I am quite pro-animal-foods. But I am also aware of the totality of the global situation in all its complexity and nuance. There are reasonable limits to everything, and animal food consumption is no exception. It is clear that people, generally, (I mean across a large population, not necessarily each and every individual within said population), do not require four pounds of meat each week. It is also clear that that level of consumption is nowhere close to what would be environmentally sustainable. And it is ALSO clear that some people — the malnourished bottom billion, especially — DESPERATELY NEED MORE ANIMAL FOODS. All of these things become clear as one studies and thinks about the issues from all pertinent angles.

Adele:
“The only “animal foods” that we’ve increased our consumption of since 1970 are poultry and fish, and the increase calories contributed by these two categories of “animal foods” isn’t even half of the increase in number of calories contributed by flour and cereal products.”

Perhaps so, but that was not my point. I said that meat consumption in the U.S. is vast (by any standard, in the world in which we live), and that is true — and more true than ever, i.e. relative to a half- or 2/3-century ago. My statements are based on unarguable statistics. Four pounds per week per capita is a LOT of meat, by the standards of the world in which we live. “Vast” is an appropriate word. Perhaps this level of consumption might not be vast on some other planet; but on this one, it is.

Adele:
“The advice might not have been intended to result in the consumption of Snackwells, but the implication is that it nevertheless had that effect. See? Effect.”

Yes, good point. However, see below.

Adele:
“So, then, where is the real origin of this problem? Shame on you, Evil Food Industry, for creating products that fit the dietary advice that was being given out?”

Yes, that’s right. Shame on the food industry. They perverted the recommendations. The spirit of the recommendations was correct enough, but the food industry went with the letter of the thing rather than the spirit of it. Now, you could say that they can’t be blamed because they are just trying to maximize shareholder value, etc. Well, maybe that is correct, but if it is, then we are saying that corporations cannot ever be morally culpable. And if THAT is true, then… (I won’t continue, else this will go into a long-winded discussion of political economics).

Apart from that, you are right that the guidelines as written could have been a lot better. See below.

Adele:
“Shame on you, greedy lazy Americans”

I did not say that. For the record.

Adele:
“Maybe, just maybe, we should have left well enough alone and not have given out that (untested, unsubstantiated, controversial) advice in the first place.”

Yes, “maybe, just maybe”. Hindsight is always 20:20. In hindsight, the dietary recommendations of 1977 could have been much better. Instead of specifying higher carb intake, they should have specified more whole plant foods, regardless of carb content. There should have been greater emphasis on EXTRINSIC sugars and fats, rather than simply tarring “fats” generally. (But then, the nomenclature — “extrinsic” — had not been used, and would not be used for another quarter century.) Many things could have been improved. But then, that’s always the way it is, isn’t it? We learn over time and improve, and the things we thought 10, 20 and 30 years ago get modified or even, sometimes, overthrown. And yet we don’t stop trying, do we?

Some of the 1977 recommendations were spot-on by anyone’s lights. For example, the idea of reducing sugar to 15% of calories. Does anyone, anywhere, regardless of where they fall on the diet opinion spectrum, disagree with that? I would hope not. Americans STILL eat upwards of 150 pounds of sugar per year, i.e. 3 pounds per week, or about 5000 calories per week. That’s incredible. And incredibly bad. It is a shame that no one listened to THAT aspect of the 1977 advice, eh? Do you think that might have had something to do with the current obesity/diabetes/diabesity epidemic?

Adele:
“We were neither fat nor sick at the time.”

Actually, we were quite sick at the time. Surely you know this (?). Cardiovascular disease was rampant, more so than today, peaking in the late 1960s and declining drastically since. See here, scroll down to Figure 1:http://circ.ahajournals.org/content/102/25/3137.full

It is interesting to note that the dramatic decline in cardiovascular disease coincided with the great increase in obesity. WHY this might be so, I don’t know, except to mention that smoking was declining as well. Surely the fact that smoking was falling explains some, though not all, of the CVD decline. But you would think that increased obesity — with its hyperinsulinemia, oxidative stress and inflammation, dyslipidemia, etc. — would more than make up for that; i.e. that CVD would be more prevalent than ever. But it isn’t. I am not trying to make a point here, just observing an interesting paradox.

Adele:
“On a more personal level, I am a person who got fat and sick eating a low-fat, vegetarian, home-cooked diet. I counted my calories. I exercised. It didn’t work & in fact, it made things worse. This is where Alan gets to tell me I was somehow deluding myself, cuz I love that part”

Adele, I think that you, and every person, should experiment with different diets and find out what works for them. I don’t argue with your experience, or anyone’s experience. Why would you think otherwise? Why would you think that I would accuse you of “deluding” yourself?

However, saying what I just said does not mean that no general dietary recommendations should ever be issued. The general recommendations are simply a context in which (or OUT of which, as the case may be) personal experimentation should proceed.

You seem to think — from the tone of your comments — that official dietary recommendations are some sort of iron laws, issued by Stalinistic authorities. But that is not so. No one is forcing you, or anyone, to cleave to a foreign dietary ideology. They are just recommendations — and not bad ones at that, even the 1977 ones (for all their warts). If Americans HAD actually increased their consumption of fiber-rich whole plant foods, while decreasing refined sugar to 15% of calories, and decreasing SLIGHTLY their intake of fatty meats, as recommended in 1977, our nation’s health would undoubtedly be better than it is today.

If you find that you really must eat red meat four times daily in order to feel well, then do it; no one will stop you. A minority of people may have that requirement. Most of us, however, don’t — and a good thing, because the planet could not support billions eating in that style. Even those who have a (seemingly) big red meat requirement would probably find, with further experimentation, that the quantity would not need to be large. Even small amounts of meat have beneficial effects on digestion (HCl secretion) and iron absorption from other foods. Red and other meat can be used as a condiment or in sauces, as is done traditionally in Asia, rather than as a main course, and provide important health benefits for many people who need them. (And many people DO in fact need them, as I stated above. Particularly but not exclusively menstruating and pregnant women.) It is quite possible that some people who think they need a pound of red meat per day might actually only need a couple ounces. The answers can only come from personal experimentation. Dietary guidelines SUGGEST that one eat less red meat; they don’t compel it, and are not intended to.

I am not a vegetarian or a vegan, much less a radical vegan ideologue. I am not opposed to the eating of red meat, or any other food, necessarily. And neither (from what I can tell) are any of the dietary guideline-writers.

Adele:
“Alan seems pretty anxious to defend the dietary status quo.”

I do?

“Status quo” means the existing state of affairs. I’m on record as saying that what Americans typically eat is “terrible”. The existing state of affairs (status quo), dietarily, is what Americans typically eat.

Why do you say that I am anxious to defend this, when I have denounced it in no uncertain terms?

Last: I don’t know what the quote from Ian Wright (your last paragraph) has to do with our discussion. If you go to the link that you provided, you see that the context of his remark was a discussion of the role of exercise (versus diet) in obesity. We were not discussing that. Also, I don’t agree with Wright, FWIW.

omg. First you have to get “consumption” and “availability” straight. Your citation refers to “availability” and not even “loss adjusted availability.”
Second, you have to get “mortality,” “incidence,” and “prevalence” straight. Mortality CVD has gone down, yes. It started to decrease over a decade BEFORE the DGA were created; the down ward trend remained exactly the same after the DGA were created. We don’t collect data on CVD incidence, but prevalence has not decreased by any measure (which would make sense if fewer people are dying of it). However, even Walter Willett himself has indicated that our efforts to reduce incidence of heart disease appear to have had no effect.

But okay, let’s just pretend that the DGA had a positive effect on CVD mortality. If so that means that 1) either Americans changed their diets in the recommended ways to correspond with the “heart-healthy” diet the DGA prescribe or 2) they didn’t–instead they ate a TERRIBLE diet–but CVD mortality went down anyway. The fact that you can’t explain these contradictions is an indication that the paradigm under which you are working is insufficient to explain what you perceive as reality. You might try a different one on for size.

And it is an extremely privileged perspective to think of the DGA as completely optional. For low-income, frequently minority women in the WIC program, adherence to DGA precepts is not optional, nor is it for many school children, old people, or people in the military.

November 24, 2014. Excerpt: Dr Neal Barnard, of the George Washington University School of Medicine and Health Sciences, added: ‘Plant-based diets work in a different way than “conventional” diabetes diets. ‘We now know that type 2 diabetes is caused by insulin resistance. Getting the animal fat — and fats in general — out of the diet helps repair insulin’s ability to function.’ He told the Daily Express: ‘We tell patients they can eat as much as they want – and as much whole wheat pasta, whole grains, and brown rice as they want – as long as they’re not eating ­animal products or lots of added oils. http://www.dailymail.co.uk/health/article-2847116/How-vegetarian-CURE-diabetes-Plant-based-diets-improve-blood-sugar-levels-scientists-claim.html

Another thing. In all the articles I’ve read about trans fats over the past decade or so, I recall only one that mentioned that trans fats exist in the context of partially hydrogenated, omega-6-rich seed oils. Moreover, the fatty acid profile of partially hydrogenated oils includes omega-6 and omega-9 fatty acid chains proportionate to the percentages present in the oil prior to partial hydrogenation. Finally, trans fats are generally used in frying and baking. Consequently, trans fats are frequently consumed along with CHO.

Not the nutrition epidemiologists, that’s for sure. What I keep hearing is agreement on the level of uncertainty in the science, but lack of agreement that this uncertainty means our recommendations should be cautious and conservative rather than experimental in nature, which is what they’ve been since 1977 (or longer, if you are the AHA).

Adele, you know I worship you as a goddess and think you’re the most wonderful person who ever lived. I didn’t think I could love you any more, and then I saw this letter 🙂

I haven’t looked at the Healthy Nation Coalition website for a while, and when I visited it today I was very struck by how WHITE all the people in the photos are. It’s several clicks in before you see anyone of color. And they’re all SO YOUNG.

I know from first-hand experience how difficult it is to get any diversity in stock photography – shockingly difficult – but I think it would be worthwhile for the website designer(s) to put some effort into it. This may seem like a trivial criticism, but it does matter.

Gingerzini – I hear you loud and clear. Let me tell you, at first all we could find was white people with SALAD. 🙂 It is still a work in progress, but I’ve been stopping/starting updates because I don’t want it to be out of commission when people come looking for it. It does matter. A lot.

And thanks for the good wishes. We’ve gotten more play on this than at any time in the past, so we’ll see what happens.

Good letter. I wish, however, it contained more information about the harmful effects of excessive omega-6 intake.

Public health experts and the governments throughout the world that rely on them currently recommend saturated fats be replaced with polyunsaturated oils to prevent heart disease. Quote: “Randomized clinical trials have shown that replacing saturated fat with polyunsaturated fat reduces total and LDL cholesterol. And our comprehensive meta-analysis provides clear evidence to support the benefits of consuming polyunsaturated fat as a replacement for saturated fat.” (Note – Omega-6 linoleic acid is the predominant polyunsaturated fat in our modernized food supply.) http://www.hsph.harvard.edu/news/press-releases/replacing-saturated-fat-with-polyunsaturated-fat-linked-with-lower-risk-of-heart-disease/

In 1977 Canadian physician Wilfred Shute wrote, “I … believe that the harm done by those who advocate increasing the proportion of polyunsaturated fats and restricting animal fats in the diet is incalculable…The suggestion that these low-cholesterol products contain enough vitamin E to protect the body from the polyunsaturated fat menace is not true…A most unfortunate aspect of this problem is the American Heart Association’s activity in pushing the idea of restricting animal fats, along with the addition of polyunsaturates as a protection against arteriosclerosis and heart disease in children, even in the new-born…More and more pediatricians are placing babies on formulas high in polyunsaturated fats without supplementing these formulas with additional vitamin E, something which must always be done.” Page 18 of Health Preserver : Defining the Versatility of Vitamin E

In the early 70s animal feed researchers realized they needed to supplement the skim milk rations of veal calves with vitamin E when soybean oil was used as a butterfat replacer. Quote: “Weekly veterinary evaluation of the appearance and health of the calves revealed no abnormalities associated with the dietary treatments. The calves were examined for condition of coat, abnormalities of stance or gait, stiffness and evidence of muscular dystrophy, excitability or nervousness, and respiratory infections or abnormality. This result contrasts with the reports of others (Adams et al., 1959 a,b; Gullickson, Fountaine and Fitch, 1942) who experienced poor weight gains, bad health, and considerable mortality of calves on rations high in unsaturated vegetable fat. All the calves in our study, whether fed milk containing high or normal amounts of polyunsaturated fatty acids, received supplemental vitamin E. The presence of this vitamin E during these early growth stages may be the explanation for the very satisfactory growth and weight gains during the milk feeding period, which contrasts with the growth deficiencies and health problems encountered by Adams et al. http://www.journalofanimalscience.org/content/37/6/1419.full.pdf+html

Finally, there’s the impact of high omega-6 linoleic acid intake on brain development of foetuses and newborns. Quote: “A significant component of what makes us intelligent is created from our mother’s fat stores. Unfortunately the fats which dominate margarines and processed food stop that absorption happening and impair intelligence in children to a greater degree than was ever caused by lead. If you want your kids to be as smart as they can be then they (and you) need to immediately stop eating those fats.” http://davidgillespie.org/margarine-makes-kids-stupid-enough-eat-margarine/

One wonders. Has margarine affected the intelligence of America’s elite scientists such that they cannot see the error of their ways?

Adele, I saw your Twitter appeal to Mark Sisson and Dr. Mike Eades to support your petition. Dr. Eades ignored your appeal completely, while Mark Sisson wrote a blog post about it yet refused to sign the petition itself. Why do you suppose this happens? Leaders in the field of health and nutrition walk away when asked for the very support that could make a real, meaningful change for the future.

Mark Sisson not only wrote an amazing blog post, he signed the coalition letter (we have both that and the petition circulating). The coalition letter names will show up publicly when I put everything together, deliver the letter, and post it at HNC

As for Dr. Eades, I can’t speak for him. But sometimes folks get jaded after working on this issue for years, which he has certainly been doing, and seeing not much, if anything, change.

Hurt? Nah. It’s not about me. It would be crazy to take this personally.

We do have a lot of support from many of different quarters, over 500 individuals so far: clinicians, dietitians, nutritionists, academics, scientists–not to mention farmers, ranchers, moms, dads, writers, educators, business people. And my favorite special interest group of all, concerned citizens.

This is excellent Adele, spot on.
I would quibble about one thing – it is quite hard to argue your point 3 that omega 6 is making things worse when we look at the epidemiological data (rather than the experimental). We get stuff like this:http://www.epccs.eu/d/386/high-dietary-linoleic-acid-intake-associated-with-lower-risk-of-coronary-heart-disease-events
However, there are 3 points to consider
1) a reduction in CHD mortality from n-6 doesn’t mean a reduction in all–cause mortality. The decrease in CHD mortality occurs at the expense of an increase in death from all other causes combined (age-adjusted) – for example herehttp://www.nmsociety.org/docs/aboutfat/Skeaff-Dietary-Fat-and-Coronary-Heart-Disease.pdf
So, assuming that n-6 does protect against CHD, is it ethical to promote treatment for one disease across a population when this will result in increases in other diseases (as well as in behavioural causes of death)?
2) the new paper above claims that “9 cohort studies evaluated substitution of LA for carbohydrate showed that substituting 5% energy intake from LA for carbohydrates lowered risk with about 10%. A slightly lower risk benefit was seen for substitution of LA for SFA.”
So, to get this benefit, you don’t need to reduce SFA intake, in fact it’s a bit better if you reduce carbohydrate instead. The case for PUFA no longer supports the case against SFA.
3) some animal fats are very good sources of n-6 PUFA and all animal fats are very poor sources of carbohydrate.

I’ve taken a look at the paper you mention & I’ve been struck (once again) by the problems with meta-analyses of observational data. The first thing I want to know with any observational study is what the population being studied is like and how that relates to the findings. This information is completely obliterated in meta-analyses.

After all, observational data is not (completely) useless. My favorite quote from Michael Pollan (there aren’t many, unless you count the ones that are my favorite ones to make fun of) is this:

“We know that people who take supplements are generally healthier than the rest of us, and we also know that in controlled studies most of the supplements they take don’t appear to be effective. How can this be? Supplement takers are healthy for reasons that have nothing to do with the pills. They’re typically more health conscious, better educated, and more affluent.”

(He doesn’t mention “white,” but that’s almost always the case as well.) So in other words, not only is it NOT the supplements, it isn’t the whole grains, the fiber, the fruitsandvegetables, or the PUFA. If you want to be healthy, be health conscious, educated, affluent, and white.

I’ve read hundreds of nutrition epi studies. They all break down along the exact same lines. The group that ate fewer eggs, less saturated fat, less meat, more whole grains, etc. etc. etc. (i.e. followed a “prudent diet”) were, as a group, more educated, more affluent, and more white. They also smoked less, exercised more, and maintained their weight. No nutrition study from the Harvard datasets (Nurses’ Health Study, Health Professionals’ Follow Up Study, the Physicians’ Health Study) has ever shown anything else besides this one finding.

In contrast to this is a study done by Zamora et al. 2010, that showed that African-Americans who ate a “healthy” diet according to the DGA actually got fatter faster than African-Americans who at a less-healthy diet. In a study done by the USDA in low-income populations, the people who eat a “healthier diet” have the same rates of obesity and higher rates of diabetes than those who eat a less-healthy diet. More about this here.

So, to me, what that meta-analysis really says is, “If you are white, well-educated, affluent, and follow most/all of the other health rules, you’re good. You’ll benefit from those qualities alone & PUFA consumption may be beside the point–or at least not so harmful that it counters all of those other advantages.”

I would point out that anyone who follows the standard advice to reduce fat intake and exercise more will likely reduce the absolute amount of PUFA intake and simultaneously become more carbohydrate tolerant. (Note: Exercise speeds uptake of glucose into muscle tissue and increases glycogen storage capacity thus blunting the insulin response.)

“Preagricultural humans living on the African grassland consumed roughly 3% of energy from LA, mostly from wild animal meats. As far back as 160,000 years ago, some ancient humans living in coastal caves and harvesting marine resources would have consumed far less LA (perhaps 1% of energy). US LA intake increased threefold from 1909 to 2009, driven primarily by solvent extraction of vegetable and seed oils. With no historical or evolutionary precedent, this high LA intake has been termed a “massive uncontrolled human experiment”.

Traditional Mediterranean, rural Japanese, and other populations with very low CHD risk have uniformly low LA intakes. Two US prospective cohort studies have reported inverse associations between LA intake and CHD risk. However, because LA intake was uniformly high, severalfold higher than evolutionary intakes and those of modern groups with very low CHD rates, these studies provide little insight into optimal LA intakes. Moreover, both studies relied on food frequency questionnaires, which have well-known limitations and may not be able to disentangle the effects of LA and n-3 ALA. Controlled trials in which high-LA oils replaced TFA- and SFA-rich fats have shown conflicting results, despite the fact that LA was accompanied by large amounts of medium- and long-chain n-3 PUFAs. A single small trial testing the specific effects of LA without n-3 PUFAs found increased CHD risk. The only long-term trial that reduced n-6 LA intake to resemble a traditional Mediterranean diet (but still higher than preindustrial LA intake) reduced CHD events and mortality by 70%. Although this does not prove that LA intake has adverse consequences, it clearly indicates that high LA intake is not necessary for profound CHD risk reduction.”

Thus far there have been no trials to determine the effect on CHD events and mortality with LA intake reduced to preindustrial levels. Excerpt from the ISSFAL 2010 Dinner Debate: Healthy Fats for Healthy Hearts:

“Prof. Uauy noted an unsettled issue of great importance: the need for data comparing the effects of omega-3 PUFAs at varying backgrounds of omega-6 PUFAs. Until there are new data to sort this out, we should be cautious in defining recommendations, he stated. There was also a suggestion from the floor that AHA withdraw its advisory statement, to which Prof. Harris responded that he was all for more data, but in his opinion AHA would be unlikely to withdraw the statement. The debate concluded with agreement by all that we need a randomized con- trolled trial to compare the effect of low and high intakes of LA. The trial should have typical US intakes of omega-3 PUFAs, with 7.5% energy from LA (the current US intake) in one group and 2.0% LA (historical intake) in the other. It would study cardiac endpoints and continue for about 5 years.”

It’s been 4 years. The issue remains unsettled. Consequently, we must rely on other lines of evidence to assess the risks associated with high omega-6 linoleic acid intake. But who pays attention to biochemistry?

I agree with this analysis, for the most part. For example, SFA tends to increase in parallel with calories across quartiles, PUFA doesn’t; therefore PUFA is displacing other calories and SFA isn’t. PUFA is an essential nutrient, in some part, like protein, and this too gives it a different value from energy nutrients like CHO, SFA and MUFA. My point in raising this is not so much to express skepticism about the deleterious effects of increasing omega-6, as to show how the best evidence for omega-6 benefits doesn’t actually support the way PUFA is promoted in the DGA as preferable to SFA (when it’s equally preferrable to MUFA and CHO) or when they try to limit fat (this is insane, as PUFA only exists as a component of fat – if you replace CHO with butter or coconut oil, you’re getting a little more PUFA).